Wednesday, September 8, 2010

Valid vs. Strong Argument

In order to say that an argument is valid, the premises should be true as well as the conclusion. It is not a valid argument if the premises are true but the conclusion is false. When stating a valid argument usually the arguments are based on facts or are plausible, which supports the statement and makes the argument stronger, in comparison to using how people perceive things or share their opinions. As an example of a valid argument:


In order to take the WST, students at SJSU have to pass the English 1A and English 1B courses.

Jasmine is a student at SJSU and passed the WST last semester.

Therefore Jasmine already took English 1A and 1B.

As students at SJSU, we know that before we can take the WST, we have to pass English 1A and English 1B. Because Jasmine is a student at SJSU and she passed the WST, we can strongly conclude that she took English 1A and 1B classes.

On the other hand, strong arguments can have true premises, but a false conclusion. However, even if the premises are true and it might seem like the argument is strong, there is still a possibility that the conclusion does not agree or support the premises. For example:

Jeremy passed English 1A and English 1B.

Jeremy is qualified to take the WST.

Jeremy will pass the WST.

The given example shows that Jeremy passed the English 1A and 1B, and is qualified to take the WST. The premises are true and are strong arguments. However, it does not mean that just because he took the required courses that he will pass the WST. We could only assume that he would pass the test, but there’s also a possibility that he will fail it. It may be because Jeremy could still be lacking some writing skills for the WST even if he passed the required classes.

2 comments:

  1. Your explanation in the first paragraph is very clear and easy to understand. The example of a valid argument that you used was a great example.In your example, there is no way that the premises could be true and the conclusion false at the same time. The example that you used for a strong argument was also a great example. It is true that just because someone is qualified to take the WST, there is no guarantee that they will pass it. This is clearly a strong argument because there is a possibility that the premises can be true and the conclusion false at the same time. Overall, very informative post and great examples.

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  2. I really like this example of valid verse strong arguments. The valid one is good because the conclusion follows the premises. Because Jasmine passed the WST, we know she has taken 1A and 1B because it is a school requirement. Unless, however, there were some weird circumstance where a student was allowed to take it without taking the courses, but such an occasion has never been known. The strong argument is a good example because it is very plausible, yet there are a couple flaws. For all we know Jeremy barely passed the classes with a “C” and although he is eligible for the WST, there is a good chance he still doesn’t pass. Very good post!

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